Method of grinding spices



y 2', 1963 F. E. KASBAUM 3,096,180

METHOD OF GRINDING SPICES Filed Sept. 28, 1961 INVENTOR.

United States Patent 3,096,180 METHOD OF GRINDING SPICES Felix E.Kasbaum, Chicago, 111., assignor to H. J. Mayer & Sons Co., Inc.,Chicago, 111., a corporation of Illinois Filed Sept. 28, 1961, Ser. No.141,368 Claims. (Cl. 99-140) This invention relates to a method ofgrinding spices. In particular, this invention relates to a method ofgrinding or comminuting dry natural spices with substantially nodetectable loss in the flavoring, aromatic and color charac teristics ofthe spices.

All spices are aromatic or odoriferous, and many are taste or feelingstimuli. The most satisfying flavors of spices are chemically complex,stimulating taste, mouthfeel and odor. The preservation of this degreeof complexity of flavoring is necessary for fullness or richness ofeffect. However, the essential oils, delicate esters and other 'agentsresponsible for this effect are highly sensitive to destruction by heatand oxidation.

The loss of these valued and desired elements is particularly acuteduring the grinding of the spices, resulting not only in a substantialweight reduction in the comrninuted product but also in a lowering inquality due, among other factors, to changes in flavor, aromatic andcolor properties. Conventional methods of grinding spices have attemptedto alleviate these problems by performing the grinding operation insubstantially enclosed chambers which are not necessarily air-tight butwhich reduce the degree of oxidation of the desired flavoring andaromatic components of spices. The extent of the destruction or loss ofthese components may be somewhat further reduced in accordance withstandard practices by employing a water-jacketed grinding chamber. Theconstant circulation of water about the periphery of the chamber removesto a degree the heat generated during the grinding operation and tendsto reduce volatilization of desired components.

These measures, however, by no means have provided an adequatelysatisfactory solution to the problems encountered in spice grindingoperations. This is evidenced by the fact that conventional grindingapparatus must be operated at reduced speeds to prevent the developmentof excessive heat within the chamber. Even with such precautionarymeasures, burning or scorching of the spices occurs, resulting inclogging of the screens through which the ground spices must pass,necessitating a cessation of operations to remove the obstructingmaterial. The reduced operating speeds coupled with the inevitable workstoppages have obvious economic disadvantages not only from thestandpoint of substantially reduced production rates but from the factthat quality of the final product can be and is adversely afiected.

As an outgrowth of reduced operating speeds, employed in conventionalmethods of grinding spices, there exists still another importantshortcoming in such methods centering around the matter of obtainingdesirable particle size in the ground spices. In this connection,present methods of grinding spices commonly employ grinding aids toachieve proper particle size. Such aids in themselves possess none ofthe characteristics of spices and serve only the function of anadulterant, increasing the volume of product passing through thegrinding apparatus but decreasing the concentration of the desired Spicein the end product. A truly high quality spice is thus unattainable withconventional methods of grinding wherein such agents are utilized.

In accordance with the preferred practice of this invention, I introducea spice into a grinding chamber where it is commingled with anon-oxidizing gas having good heat exchange properties whereby to attaina desired temperature within the chamber, and then grind the spice inthe chamber while substantially maintaining that temperature PatentedJuly 2, 1963 by controlling the discharge of the ground spice from thechamber.

My method may be utilized in connection with the grinding of any spice,or combination thereof, with equally effective results. Examples ofspices that may be subjected to size reduction in accordance with thisinvention are black and white pepper, nutmeg, sage, marjoram, al1-spice, clove, cinnamon, thyme, celery, anise, savory, Wintergreen,parsley, rue, sweet basil, tarragon, mustard, Caraway, tonka beans,angostura, Cassia, ginger, garlic, onion, turmeric, paprika, rosemary,Wormwood, jasmine, slippery elm, wild-cherry bark, witchhazel, getianroot, cardamon seed, cumin, coriander, and the like.

In carrying out my method any grinding apparatus capable of beingenclosed at the point of size reduction may be utilized. Examples ofapparatus suitable for the purposes of this invention are stone mills,hammer mills, ball mills, roller mills, abrasion mills, and the like.The modifications to such equipment to adapt it to my method are notextensive and present no burdens from the standpoint of economicconsiderations, or otherwise.

In order to illustrate the above referred to modifications, and tosimplify understanding of my invention, I have, on the attached sheet ofdrawings, shown a typical embodiment of apparatus having utility for thepurposes of carrying out my method. Referring now to the drawings:

I FIG. 1 is a perspective View of a hammer mill with associatedequipment for introducing spices and liquified gas thereinto.

FIG. 2 is a vertical sectional 22 of FIG. 1.

FIG. 3 is an enlarged exploded view showing details of the gas inlet.

FIG. 4 is a perspective view of an expansion plug.

In accordance with the preferred practice of this invention, ungroundspice is placed in a hopper 10 provided with suitable drive feed meanssuch as auger or worm screw 11. The screw 11 at one end is connected toa source of power, not shown, and at its other extremity is suitablyjournalled at the coupling 12 between the hopper 10 and a mill orgrinder 13. The spice from the hopper 1G is conveyed at a desired rateby the screw 11 into a chamber 14 of the grinder 13. Positioned withinthe chamber 14 are a plurality of hammers 15 which serve to comminutethe spice to proper size. The mill 13 is provided with a screen 16through which the ground spice passes to a discharge outlet 17.

The chamber 14 is formed in part by a cover 18 which is provided with aninlet 19 for introducing a non-oxidizing gas having good heat exchangeproperties into the chamber 14. In the preferred embodiment illustrated,the inlet 19 is approximately 1 inch in diameter and is pro vided withexternal threads 26'. The inlet 19 is adapted to receive an expansionplug 21 provided with a conical inlet portion 22 and a cylindricaloutlet portion 23. The plug 21 is securely held in aligned position withrespect to the inlet 19 by means of a suitably internally threadedconnector 24 which in turn is connected to a conduit 25 leading from asource, not shown, of liquefied gas having utility for the purposes ofthis invention. A valve such view taken along line as needle valve 25may 'be provided between the source of l the gas and the inlet 19 tocontrol the rate of flow of gas into the inlet 19.

The line pressure desirably utilized in the conduit 25 will bedependent, in part, on the type of gas being employed as the coolant. Inthe case of liquid carbon dioxide, I have found that especiallydesirable results are obtained with a line pressure in the conduit 25 ofapproximately 300 psi.

The gas employed in connection with my process is.

especially desirably in a liquified state as it enters inlet portion 22of the plug 21. As the liquid gas passes through outlet portion 23 ofthe plug 21 it is difiused and expanded in the inlet 19 from where itpasses in a gaseous state into the chamber 14. There it is commingledwith spices being ground by the hammers 15 of the mill 13. The difiusionand expansion of the gas are critically influenced by the size of theorifice in inlet portion 22 of the plug 21 and this dimension will varyaccording to the type of gas used, spice being ground, and the rate atwhich it is ground. If liquid carbon dioxide is utilized as the coolant,the orifice of the inlet portion 22 preferably ranges from 0.030 inch to0.050 inch in diameter, and may vary by intervals of 0.005 inchdepending on the spice being ground and on the rate at which it isground.

The liquid gases having utility for the purposes of my inventio havebeen referred to herein as those that are non-oxidizing and have goodheat exchanging properties.

The heat exchanging characteristics of the gas will be determined by thetemperature at which the gas passes from the liquid to the gaseousstate. For example, if a gas has a temperature'in the range of about 2-0F. immediately following the transformation, it has good heat exchangingproperties for the purposes of this invention. Examples of liquid gaseswhich give good results are carbon :dioxide, nitrogen, ammonium,chlorinated-fluorinated hydrocarbons such as the Freons, and the like.Certain of the gases that may be employed give off objectionable andnoxious odors at the point of discharge of the ground spices and,therefore, desirably involve the utilization of equipment to remove, andprotect against, such odors.

The temperature of the chamber 14 during the grinding operationadvantageously should range from about -69 F. to about 30 F. Thetemperature may be appro-v priately regulated by controlling the rate ofdischarge of the ground spices through the outlet 17 of the mill 13. Thetemperature at the discharge outlet 17 most desirably ranges from about30 F. to about 60 F. The objects of this invention are eifectivelyachieved at a discharge temperature in the range of from about 40 F. toabout 60 F. with optimum results being obtained at a dischargetemperature of from about 50 F. to about 55F.

Under normal operating conditions, the temperature of the chamber 14will be approximately 30 F. lower than the discharge temperature atoutlet 17. The chamber 14 need second of the order of 0.5 second, butmay range to 4 taina'ble production rate can be maintained for extendedperiods Without burning or scorching the spices being ground. This hasthe very desirable concomitant efiect of eliminating screen clogging andthe resultant shutdowns to free the screen of adhering burned orscorched material.

The screen 16 illustrated in FIG. 2 of the drawings is of conventionaldesign and construction, and the mesh size seconds, and thus for allpractical purposes is almost instantaneous.

At the operating temperatures specified, the frangibility of the spiceparticles is materially enhanced, enabling them to be comminuted with.far greater facility. This greater ease in grinding, moreover, can beaccomplished without the use of grinding aids In addition to renderingthe spice particles more susceptible to grinding, the temperatures atwhich my method is carried out permit the grinding apparatus to operateat substantially higher rates than is possible in conventional methods.For example, employing liquified carbon dioxide as the coolant andutilizing apparatus such as is illustrated in the accompanying drawingsequipped with a 7 /2' horsepower, 200 volt motor, the hammer mill headmay be operated at 1,750'revolutions per minute resulting .in'aproduction rate of from 200 to 500 pounds per hour.

This rate of production is approximately 10 times that obtained in aconventional method employing the same grinding equipment. Furthermore,this heretofore unatthereof may vary from inch to 0.01 inch. As theground product passes through the screen it is discharged through outlet17 into a suitable container. It is especially desirable to provide atthe point of discharge some insulation of the product from theatmosphere. This may be effectively accomplished by fitting the outlet17 with a skirt 27 of sufficient length to form an enclosed dischargepassage from the outlet 17 to a container, not shown.

Spices ground in accordance with the method of this invention are ofextremely high quality. There is no detectable loss in weight, duelargely to the preservation of the volatile components of the spices,and the normal approximately 10% color loss experienced in conventionalmethods of grinding spices is eliminated. The absence of grinding aidsgives a highly concentrated end pnoduot. The texture of the product,moreover, is in no way affected by the temperatures employed in mymethod.

Any increased costs, and these are relatively slight, in the use of themethod of this invention are fully ofiset not only by the substantiallygreater production rates the method makes possible but by the greatervalue of the high quality product obtained in accordance with themethod.

' The foregoing detailed description has been given for purposes ofexplanation only and no unnecessary limitation should be understoodtherefrom, it being understood that numerous changes may be made in themanner of carrying out the invention, all within the spirit of theguiding principles and teachings provided herein.

What I claim is: I

1. An improved method or grinding spices which comprises introducing thespices to be ground into a chamber, commingling with the spices in thechamber a non-oxidizing gas having good heat exchanging propertieswhereby to obtain a temperature within the chamber of from about -69 F.to about 30 F., and grinding the spices i the chamber while maintainingthe temperature by controlling the rate of discharge of the groundspices from the chamber.

2. An improved method of grinding spices which oomprises introducing thespices to be ground into a chamber, comming'lirrg with the spices in thechamber a non-oxidizing gas having good heat exchanging propertieswhereby to obtain a temperature within the chamber of from about -6'9 F.to about 30 F., grinding the spices in the chamber while maintaining thetemperature in the aioresaid range by controlling the rate of dischargeof'the ground spices from the chamber, and discharging the ground spicesfrom the chamber at a temperature of from F. to about F.

3. An improved method of grind-ing spices which comprises introducingthe spices to be ground into a chamber, comrningling with the spices inthe chamber a nonoxidizing gas having good heat exchanging propertieswhereby to obtain a temperature within the chamber of from about =69 F.to about 30 F., grinding the spices in the chamber while maintainingthe. tempenature in the. aforesaid temperaturerange by controlling therate of discharge of the ground spices from the chamber, and dischargingthe ground spices from the chamber at a'temperature of from about 40 F.to about 60 F.

4. An improved method of grinding spices which comprises introducing thespices to be ground into a chamber, comrningling with the spices in thechamber a nonoxidizing gas having good heat exchanging propertieswhereby to obtain a temperature within the chamber of about -30 fromabout 69 F. to about 30 F., grinding the spices in the chamber for aperiod of from about 0.5 second to about 4 seconds while maintaining thetemperature in the aforesaid temperature range by controlling the rateof discharge of the ground spices from the chamber, and discharging theground spices from the chamber at a temperature of from about 30 F. toabout 60 F.

5. An improved method of grinding spices which comprises introducing thespices to be ground into a chamber, coinmingling with the spices in thechamber carbon dioxide gas at a temperature whereby to obtain atemperature within the chamber of from about -69 F. to about 30 Fgrinding the spices in the chamber while maintaining the temperature inthe aforesaid temperature range by controlling the rate of discharge ofthe ground spices from the chamber, and discharging the ground spicesfrom the chamber at a temperature of from about 30 F. to about 60 F.

6. An improved method of grinding spices which comprises introducing thespices to be ground into a chamber, commingling with the spices in thechamber nitrogen gas at a temperature whereby to attain a temperaturewithin the chamber of from about 69 F. to about 30 F., grinding thespices in the chamber while maintaining the temperature in the aforesaidtemperature rmge by controlling the rate of discharge of the groundspices from the chamber, and discharging the ground spices from thechamber at a temperature of from about 30 F. to about 60 F.

7. An improved method of grinding spices which comprises introducing thespice to be ground into a chamber through one inlet thereof, injectinginto the chamber through another inlet thereof a non-oxidizing gashaving good heat exchanging properties whereby to obtain a temperaturewithin the chamber of from about 69 F. to about 30 F., grinding thespices in the chamber while maintaining the temperature in the aforesaidrange by controlling the rate of discharge of the ground spices from thechamber, and discharging the ground spices from the chamber at atemperature of from about -30 F. to about 60 F. while shielding thespices from the atmosphere.

8. An improved method of grinding spices which comprises introducing thespices to be ground into a chamber through one inlet thereof, sprayinginto the chamber through another inlet thereof a non-oxidizing gashaving good heat exchanging properties whereby to obtain a temperaturewithin the chamber of from about -69 F. to about 30 F., grinding thespices in the chamber while maintaining the temperature in the aforesaidrange by controlling the rate of discharge of the ground spices from thechamber, and discharging the ground spices from the chamber at atemperature of from about 40 F. to about 60 F. while shielding thespices from the atmosphere.

9. An improved method of grinding spices which comprises introducing thespices to be ground into a chamber through one inlet thereof, injectinginto the chamber through another inlet thereof a non-oxidizing gas in adiifused and expanded state having good heat exchanging propertieswhereby to obtain a temperature within the chamber of from about 69 F.to about 30 F., grinding the spices in the chamber while maintaining thetemperature in the aforesaid range by controlling the rate of dischargeof the ground spices from the chamber, and discharging the ground spicesfrom the chamber at a temperature of from about F. to about F. Whileshielding the spices from the atmosphere.

10. An improved method of grinding spices which comprises introducingthe spices to be ground into a hammer mill, commin'gling with the spicesin the chamber a non-oxidizing gas having good heat exchangingproperties whereby to obtain a temperature within the mill of from about-69 F. to about 30 F., holding the spices in the mill for a period offrom about 0.5 second to about 4 seconds while maintaining thetemperature in the aforesaid range by controlling the rate of dischargeof the ground spices from the chamber, and discharging the ground spicesfrom the chamber at a temperature of from about 30 F. to about F. whileshielding the ground spices from the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS1,924,059 Hoskins Aug. 22, 1933 2,235,315 Donnelly Mar. 18, 19412,583,697 Hendry et a1. Jan. 29, 1952

1. AN IMPROVED METHOD OF GRINDING SPICES WHICH COMPRISES INTRODUCING THESPICES TO BE GROUND INTO A CHAMBER, COMMINGLING WITH THE SPICES IN THECHAMBER A NON-OXIDIZING GAS HAVING GOOD HEAT EXCHANGING PROPERTIESWHEREBY TO OBTAIN A TEMPERATURE WITHIN THE CHAMBER OF FROM ABOUT -69*F.TO ABOUT 30*F., AND GRINDING THE SPICES IN THE CHAMBER WHILE MAINTAININGTHE TEMPERATURE BY CONTROLLING THE RATE OF DISCHARGE OF THE GROUNDSPICES FROM THE CHAMBET.